Full-protection circuit breakers such as these with residual-current-operated components and line-protection circuit breakers, which, overall, form a circuit breaker which interrupts a current path to be monitored not only in the event of a short circuit occurring but also in the event of a thermal overcurrent and furthermore also in the event of a fault current occurring, are known in principle. The two devices, the line-protection circuit breaker and the residual-current-operated component, are coupled to one another such that the line-protection circuit breaker is disconnected when the residual-current-operated component trips, but the residual-current-operated component remains in the position ready for tripping when the line-protection circuit breaker responds, provided that the short circuit or overcurrent was not associated with a fault current. Full-protection circuit breakers such as these are therefore used at the same time for protection of the line network to be monitored against short circuits and overloading, for example for prevention of electrical accidents caused by line defects and the like.
DE 44 13 418 A1 discloses a full-protection circuit breaker of this generic type having a line-protection circuit breaker and a residual-current-operated protection part which can be fitted thereto. The release element of the latching mechanism of the residual-current-operated protection part is in this case coupled to the line-protection circuit breaker by means of a coupling element. The coupling element in this case interacts with the tripping lever of the line-protection circuit breaker such that, when the residual-current-operated protection part trips, the coupling element always acts on the tripping lever of the line-protection circuit breaker in the direction of unlatching of the latching point of the latching mechanism of the line-protection circuit breaker. Furthermore, the residual-current-operated protection part and the line-protection circuit breaker are connected to one another via a slide. By interacting with a lever mechanism in the residual-current-operated component, the slide ensures that the residual-current-operated component can be operated even when the line-protection circuit breaker has tripped, for example as a result of an overcurrent.
When, after the residual-current-operated component has responded, the reason for this, that is to say the occurrence of a fault current, has decayed again, then the latching mechanism of the residual-current-operated component remains in its tripped position until it is reset by manual operation of the switching toggle of the residual-current-operated component. Only once the latching mechanism of the residual-current-operated component has been manually reset is the coupling element once again moved to a position in which the action of the tripping lever of the line-protection circuit breaker in the direction of unlatching of the latching point of the latching mechanism of the line-protection circuit breaker cancelled, and the latching point of the latching mechanism of the line-protection circuit breaker can thus be latched again.
Only then can the line-protection circuit breaker be reconnected manually via its switching toggle.
Because of the mechanical lever step-up ratio in the residual-current-operated component, which lever step-up ratio translates the rotary movement of the switching toggle to a linear movement of the coupling element, a certain lead of the switching toggle of the residual-current-operated component is necessarily required. This means that the switching toggle of the residual-current-operated component must first be rotated through a specific angle in the direction of the connected position and only then is the coupling element moved to a position in which it allows relatching of the latching point of the line-protection circuit breaker.
When the line-protection circuit breaker is intended to be reconnected after tripping of the residual-current-operated component and the disconnection of the line-protection circuit breaker which necessarily results from this, the residual-current-operated component must be connected first of all, and only then is it possible to connect the line-protection circuit breaker.